1. Field of the Invention
The present invention relates generally to a suspension seat employing a magneto-spring and, in particular but not exclusively, to a weight adjusting mechanism for adjusting for the weight of a seat occupant on the suspension seat.
2. Description of the Related Art
In recent years, accompanying the practical use of permanent magnets that have a high coercive force and high residual magnetic flux density, research is flourishing on magnetic controls for magnetic levitation, magnetic bearings, dampers employing a magnetic fluid, etc. Because magnetic levitation damping technology makes it possible to support physical objects with no actual physical contact, its merits include reduction of problems related to friction and wear, the capability for motion at very high speeds, and low levels of vibration and noise.
Recently, a suspension seat employing a magneto-spring in which like magnetic poles are opposed to each other has been proposed, and research thereon is advancing.
Although suspension seats have a weight adjusting mechanism for absorbing the weight difference between seat occupants, the actual situation in the suspension seat employing the magneto-spring is such that the detailed construction is still open to further discussion and no sufficient investigation has been conducted on the weight adjusting mechanism.
In conventional suspension seats employing metal springs, weight adjustment is generally conducted by a dial-type adjuster in which the tension of the metal springs is changed. Such weight adjustment is disadvantageous in that the range for adjustment is wide and adjustment is troublesome.
The present invention has been developed to overcome the above-described disadvantages.
It is accordingly an objective of the present invention to provide a weight adjusting mechanism for a suspension seat that is superior in operability and has a simple construction.
In accomplishing the above and other objectives, the weight adjusting mechanism according to the present invention includes a lower frame and an upper frame vertically movably mounted on the lower frame via a link mechanism. The upper and lower frames have respective permanent magnets secured thereto with like magnetic poles opposed to each other. An operation member is pivotally mounted on the upper frame, and a metal spring having a first end connected to the link mechanism is connected at a second end thereof to the operation member to produce a lifting force of the upper frame so that weight adjustment may be conducted by changing an elastic force of the metal spring.
By this construction, the weight adjustment can be conducted merely by moving the operation member, making it possible to provide an easy-to-operate weight adjustment mechanism of a simple construction.
Conveniently, the weight adjusting mechanism further includes a locking member mounted on the operation member for locking the operation member, wherein the operation member is movable between a locking position where the operation member is locked by the locking member and a lock-released position where locking of the operation member is released, and wherein the lifting force of the upper frame at the locking position is greater than that at the lock-released position.
By this construction, the weight adjustment can be conducted merely by moving the operation member between the locking position and the lock-released position.
Again conveniently, the locking member is rotatably mounted on the operation member, and the upper frame has a stopper, wherein the operation member is locked by first moving the operation member at the lock-released position towards the locking position, and by subsequently bringing the locking member into contact with the stopper to rotate the locking member, and the locking of the operation member is released by bringing the locking member at the locking position into contact with the stopper again to further rotate the locking member.
This construction simplifies the locking and the lock-releasing of the operation member, thus enhancing the operability of the weight adjusting mechanism.